The Combined Effect of Irrigation and Nitrogen Application on Yield, Water Consumption of Oat and Soil Salinity

Abstract

【Objective】 Irrigation and fertilization are essential to safeguarding crop yields, but they have detrimental impacts on the environment and could result in soil salinization. The objective of this paper is to study the effects of different combinations of irrigation and nitrogen application on water consumption, yield of oat , as well as soil salinity. 【Method】 The experiment was conducted in pots repacked with soil taken from a saline-alkali area, with the Bayou No.18 cultivar used as the model plant. The experiment consisted of two irrigation amounts: 120% (W1) and 100% (W2) of the evapotranspiration, and four nitrogen applications: 0 (N0), 70 kg/hm2 (N1), 140 kg/hm2 (N2), and 210 kg/hm2 (N3). In each treatment, we measured the yield, water consumption of the oat, as well soil salinity of each pot. 【Result】 W1 and N2 significantly (p<0.05) increased water consumption, oat yield, and water use efficiency. Increasing nitrogen application led to an increase in soil salinity. W1 was more effective in leaching salt and reducing salt content in the root zone. The agronomic use efficiency and yield of nitrogen fertilizer were the highest in N2, reaching 2.9 kg/kg and 1 079.0 kg/hm2, respectively. 【Conclusion】 Irrigating 120% of ET combined with 140 kg/hm2 of nitrogen fertilization can maintain soil water content and electrical conductivity at 22.02%~23.39% and 2.24~3.03 dS/m, respectively. They improved the use efficiency of irrigation water and the nitrogen fertilizer, thereby increasing the oat yield.

Keywords

• water-nitrogen coupling
• oat
• water consumption
• yield
• soil salinity